. >> lots of questions that tamerlan, the older brother, had been questioned before by the fbi, in 2011, at the request of the russian government. >> well, that's right. but, think about this, george, there are hundreds of thousands of young adults in this country that visit extremist islamic websites, he was one of them, so the question is, what line do you draw that we continue the investigation? or do we go and interview, make a decision on other intelligence that were not going to pursue an active case against him? >> you're already seeing some congressmen, peter king, criticizing, saying this was a missed opportunity. >> that's great to say. but when you have literally hundreds of thousands of people you want to keep track of, you want to prioritize. they're going to miss one every once in a while. when you approach them, when you interview them or do their background, they may not have radicalized to the level of what we saw on monday. >> going to websites wouldn't be enough? >> absolutely not. >> the older brother went back to russia in 2012, was there for several months. we know